JP2935817B2 - Hole forming method for forming a tapered through hole in a workpiece by pressing and tool for forming the hole - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drilling method and a drilling tool suitable for forming a tapered through hole in a workpiece by pressing, and more particularly, to a drilling tool therefor. For example, in a pipe joint that can lock a plug and a socket using a locking sphere, a hole processing method suitable for processing a tapered hole formed on the socket side for holding a locking sphere by pressing, and The present invention relates to the hole drilling tool.

[0002]

2. Description of the Related Art A locking mechanism used in a conventional pipe joint will be described below with reference to the drawings . FIG. 9 is a sectional view of the pipe joint. In the figure, the pipe joint comprises a socket 20 and a plug 30, a plug 30 having a flow hole 33 is provided with a large-diameter portion having a circumferential groove 31 with which a locking sphere (described later) provided on the socket 20 engages; A small diameter portion 32 is provided on the free end side of insertion into the socket. On the other hand, the socket 20 having the communication hole 26 includes a front cylinder 21 into which the plug 30 is inserted, and a rear cylinder 21 ′ connected to the front cylinder 21 with a screw 25. A packing 22 is disposed between the rear cylinders 21 ′, and a valve body 24 urged toward the packing 22 by the urging force of a spring 23 is provided. When the plug 30 is not inserted into the socket, the valve body 24 comes into contact with the packing 22 by the urging force of the spring 23 to block the flow hole 26. Also, the front cylinder 21
A tapered through-hole 27 is formed in the diametrical direction at a position at equal intervals in the circumferential direction, and a locking sphere 28 is provided in the tapered through-hole 27 to the inner surface of the front cylinder 21. The portion protrudes and is fitted so as to be engageable with the peripheral groove 31 of the plug 30. An operation sleeve 29 resiliently mounted by a spring 29a is fitted around the outer periphery of the front cylinder 21. The sleeve 29 has a pressing surface 29b for pressing the locking sphere 28 in a centripetal direction. .

When the plug 30 is inserted into the socket 20 in a state where the operation sleeve 29 is moved rightward in the drawing against the urging force of the spring 29a, the locking sphere 28 provided on the front cylinder 21 is The valve body 23 is also pushed rightward in the figure by the tip of the plug 30 to open the flow path, and the socket and the flow holes 26 and 33 of the plug communicate with each other. On the other hand, the locking sphere 28 is
When the operating sleeve 29 is released in a state in which the operating sleeve 29 is engaged, the sleeve returns to the illustrated position by the urging force of the spring 29a. The engaged state is maintained.

As described above, a conventional pipe joint employs a locking mechanism using a locking sphere when connecting a plug and a socket. The locking sphere 28 is housed in the tapered through hole 27 generally formed on the socket side as described above, and when the socket is assembled by the action of the tapered through hole 27. The locking ball 28 does not fall out in the centripetal direction of the front cylinder 21. By the way, the tapered through-hole 27 provided in the front cylinder 21 is usually formed at a position on the outer periphery of the front cylinder which is equally divided into a plurality of parts.
Conventionally, a through hole having this tapered shape has been drilled one by one by a taper drill using a drilling machine such as a drilling machine while determining the position on the outer periphery, and further subjected to finish processing by a reamer.

[0005]

However, machining a through-hole having a tapered shape one by one using a taper drill and a reamer is very troublesome, and the life of the taper drill and the reamer is relatively short. As a result, the number of drill and reamer exchanges has increased, and the resulting dimensional control has been difficult. Accordingly, the present invention provides a method of processing a through-hole having a tapered shape capable of forming the through-hole having the tapered shape as described above at a time by pressing, and a tool for processing the same. With the goal. By employing this processing method or processing tool, a plurality of tapered through-holes can be formed at once in a workpiece by pressing, so that the production efficiency can be greatly improved.

[0006]

In order to achieve this object, a solution adopted by the present invention is to provide a plurality of punching holes formed in the periphery and a cutting edge for deburring at the corner of the hole on the workpiece side. The die formed in each of a plurality of punches which are fitted and fixed to the outer periphery of a cylindrical sleeve which becomes a die and which are arranged corresponding to the plurality of punching holes. After a hole is punched in the workpiece simultaneously with a first punch having a smaller diameter than the hole, a second punch is inserted into the hole through the guide, and at least a part of the hole is plastically formed into a tapered shape by the second punch. Processing, and furthermore, by means of a pressing portion formed on the upper part of the second punch, the occurrence of burrs formed on the outer peripheral edge of the hole by the plastic working is prevented,
A hole forming method for forming a tapered through hole in a workpiece by a press, characterized in that burrs on the workpiece side generated at the time of punching are cut by the cutting edge formed in a die. A tool used when a through-hole having a tapered shape in part is formed by pressing, the tool includes a first punch having a small diameter for punching a hole in the workpiece, and the hole being formed by using the hole as a guide. A second punch for forming a through-hole having a tapered shape at the lower end of the hole by plastic working of the hole, and a presser for preventing generation of burrs formed on the outer peripheral edge of the hole by plastic working of the second punch. Further, the second punch has a tapered portion continuous with the outer periphery of the first punch formed at the lower end of a round bar having a predetermined length, and is slidable above the second punch. A tapered through-hole machining tool, characterized in that a presser for preventing generation of burrs formed on the outer peripheral edge of the hole by plastic working of the second punch is provided. A tool and a die used when a through hole having a shape is formed by press, wherein the tool has a small-diameter first punch for punching a hole in the workpiece, and the hole is plastically processed using the hole as a guide. A second punch, which is formed into a through hole having a tapered shape, is formed continuously in the axial direction. The die is formed separately for each of the tools, and a tapered surface is formed on the inner peripheral surface. A tapered through-hole machining tool and a die are characterized in that they are pushed out toward the inner peripheral surface of the workpiece by a taper member fitted to the inner peripheral surface.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a hole forming method for forming a tapered through hole according to the present invention will be described with reference to the drawings. FIG. 2 is an explanatory view when a through hole having a tapered shape is machined in the front cylindrical body of FIG. 1, FIG. 2 is an enlarged front view of a hole punch used in the present machining method, and FIG. FIG. 4 is an explanatory diagram of a process of forming a through hole having a tapered shape by a punch, and FIG. 4 is an explanatory diagram of a process of forming a tapered through hole by a punch having no holding portion. In FIG. 1, reference numeral 1 denotes a punch for punching a tapered through hole in a front cylindrical body as a workpiece, and 2 denotes a tapered shape which is inserted into the front cylindrical body and cooperates with the punch 1. The die is a cylindrical sleeve that serves as a die for processing a through hole having the above. The die is slidably and non-rotatably fixed to one end of a press machine via a jig (not shown). Reference numeral 3 denotes a front cylindrical body as a workpiece, which is inserted into and held at one end of the outer periphery of the die. Reference numeral 4 denotes a fixing member for fixing the front cylindrical body 3 mounted on the die. The punch 1 is slidably held at one end of a press machine (not shown) via a jig, and cooperates with a die 2 as will be described later, in the course of the advance of the punch 1, as described later. A through hole having a tapered shape can be formed in the body 3.

As shown in FIG. 2, a punching punch 1 used for processing a through hole having a tapered shape has a punch portion 1a (first punch) and a tapered portion having a tapered surface T in the axial direction in order from the tip end. 1b (second punch) and the holding portion 1c are formed continuously. The punch portion 1a has a function of performing a drilling operation on a workpiece and is formed in a circular cross section having the same diameter. The tapered portion 1b having the tapered surface T has a function of forming a tapered surface by plastically processing the inner peripheral surface of the hole by using the drilled hole as a guide. It has a tapered surface T having a length and a cylindrical portion formed continuously from the upper end of the tapered surface. The diameter of the cylindrical portion is formed in a circular cross section having a diameter larger than that of the punch portion 1a, and the axial length of the tapered surface T is a through hole having a required tapered shape in consideration of the stroke of the punch and the like. Is determined according to the shape of. Further, the holding portion 1c has a function of preventing occurrence of "burrs" formed on the outer periphery of the hole due to the plastic working.
Is more desirably formed according to the surface shape of the workpiece. The punch portion 1a and the tapered portion 1b
Are determined in accordance with the thickness of the work to be processed.

On the other hand, a die 2 arranged at the center of the workpiece forms a hole in the workpiece in cooperation with a punch during punching and discharges a cut metal piece out of the machine through the hole. It has the function to do. Therefore, as shown in FIG. 3, a hole 2a having a diameter slightly larger than the outer diameter of the punch portion 1a is formed in the die 2 at a position corresponding to the cutting edge of the punch 1.
Is provided so that the cutting edge of the punch portion can be inserted into the hole 2a. The front cylinder 3 is positioned in contact with a step 2b (see FIG. 1) formed on the outer periphery of the die 2, and is fixed by a fixing member 4 slidably provided coaxially with the die.

Next, a method for forming a tapered through hole by pressing using the above-described tool will be described. Although the front tubular body of the pipe joint is provided with a plurality of tapered through holes, the tapered through hole processing method of the present invention employs a plurality of tapered through holes. By arranging and arranging the punches in accordance with the positions of the holes, through holes having a plurality of tapered shapes can be simultaneously formed by a single pressing step. Here, the forming process will be described focusing on the processing of a through hole having one tapered shape. FIG. 3 is an enlarged explanatory view for forming a tapered through hole in a front cylindrical body as a workpiece, (a) shows a state of drilling by a small-diameter punch portion, and (b) is (a). A state is shown in which the inner surface of the hole is formed into a tapered surface T by plastic working using the hole of the formed workpiece as a guide, and "burrs" formed on the outer peripheral edge of the hole during the plastic working are prevented. .

First, when a hole is drilled in a workpiece by the small-diameter punch portion 1a, the hole 11 drilled at this time is
In press molding, as is well known, a broken surface is obtained in which the lower end of the hole is opened as shown in FIG. Next, as shown in FIG. 2 (b), the hole 11 is used as a guide, and the tapered portion 1b having a diameter slightly larger than the diameter of the hole and having a tapered surface T.
To carry out plastic working. By this plastic working, a tapered surface T is formed on the inner surface of the hole 11 as shown in FIG. The axial length of the tapered surface T formed on the inner surface of the hole 11 at this time is the same as the tapered surface T formed on the punch.
It can be changed freely by changing.

The workpiece is deformed on the outer peripheral edge of the hole 11 due to the plastic working "burrs 3a (see dotted line in the figure)".
Is formed, it is necessary to prevent the occurrence of the "burrs 3a". For this reason, the punch 1 of the present invention has a pressing portion 1c for preventing the occurrence of "burrs 3a". Even if "burrs" occur during plastic working, the tapered portion 1 having a tapered surface T as shown in FIG.
The outer peripheral edge of the hole 11 can be held down by the holding portion 1c provided above b. It is more desirable that the presser portion 1c for preventing the generation of the "burrs 3a" has a shape conforming to the outer surface shape of the workpiece (if the outer surface shape is a curved surface, a shape conforming to the curved surface). In this embodiment, a punch 1 having a flat holding portion 1c is used.

In addition, with the occurrence of "burrs 3a" during the taper processing , the front cylinder 3 is plastically deformed while the front cylinder 3 is slightly deformed, and a small gap between the die 2 and the front cylinder 3 is formed. May enter the slight gap 5 between them and generate "burrs". This “burr” is usually sheared by the corner 6 of the die 2 when the front cylinder 3 is removed from the die 2. However, if the “burr” is not sufficiently sheared and the “burr” remains, When the body 2 is assembled as a pipe joint, there is a disadvantage that the "burrs" hinder the pipe joint from being assembled. For this reason, it is necessary to form the corner 6 more sharply so that the “burr” can be completely cut by the corner 6 of the die 2.

Next, a second embodiment will be described with reference to FIG. The second embodiment relates to a die 2, which is formed by dividing the die 2 for each hole formed in the front cylindrical body 3, and using a die in order to prevent the above-mentioned "burrs" from occurring. It is characterized in that it is composed of a tapered member 47 for strongly pressing against the inner peripheral surface of the front cylinder 2.

That is, in FIG. 5, reference numeral 40 denotes a die,
The dies 40 are arranged so as to be arranged in each of holes formed by dividing the entire circumference of the front cylindrical body 3 into four equal parts, and have a U-shape as viewed from the side as shown in FIG. . A hole 4 for slidably holding the punch 1 is formed in the upper side 41 of the U-shape.
A hole 44 for forming a hole in the front cylindrical body 3 in cooperation with the hole punch 1 is formed in the lower side 43 of the U-shape. The upper surface 45 of the lower side 43 has a shape conforming to the inner peripheral surface of the front cylindrical body 3 as a workpiece (in this example, since the inner peripheral surface is circular, it has a circular shape corresponding to it). Also, on the lower surface of the lower side 43, a tapered surface 46 corresponding to a tapered member 47 (see FIG. 5) for eliminating a gap formed between the die 40 and the front cylinder by strongly pressing the die 40 is formed. Have been.
In the figure, reference numeral 4 denotes a fixing member having the same configuration as that of the first embodiment.

In order to form a tapered through-hole in the front cylinder 3 as a workpiece using this die, first, the front cylinder 3 is fixed with the fixing member 4 and the punching punch is formed. The die 40 is positioned and arranged with respect to the front cylindrical body 3 in accordance with the above, and the die 40 is pressed against the front cylindrical body 3 and fixed while pressing the taper member. By operating the punch with the die 40 fixed in this manner, the first
A tapered hole can be formed in the front cylindrical body 3 as in the embodiment. At this time, since the die 40 is strongly pressed against the front cylinder 3 by the tapered member 47, the gap between the die 40 and the front cylinder 3 is eliminated, and the generation of burrs can be suppressed to a minimum. In the above example, the die 40 is formed in a divided manner. However, a die having a shape like a collet chuck by forming a slit in a cylindrical sleeve may be used.

Further, a third embodiment will be described with reference to FIGS. The third embodiment relates to the punch 1 and is characterized in that the holding portion 1c of the punch is formed separately from the punch 1. FIG.
In the punching punch 1 used for processing a through hole having a tapered shape, a punch body 1a (first punch) is formed in a punch body in the axial direction from a tip end portion as shown in FIG. The portion 1b (second punch) is formed continuously, and a pressing portion 50 is slidably provided on the outer periphery of the punch body.

A method of forming a through hole having a tapered shape by this hole punching will be described. FIG. 8A shows the state of the hole formed by the small-diameter punch portion, and FIG. The figure shows a state in which after the inner surface of the hole is formed into a tapered surface by plastic working using the hole of the workpiece as a guide, the “burrs” formed on the outer peripheral edge of the hole during the plastic working are pressed by the pressing portion 50.

First, when a hole is drilled in a workpiece by the small diameter punch portion 1a, the hole 11 drilled at this time is
In press molding, as is well known, a broken surface is obtained in which the lower end of the hole is opened as shown in FIG. Next, as shown in FIG. 2 (b), the hole 11 is used as a guide, and the tapered portion 1b having a diameter slightly larger than the diameter of the hole and having a tapered surface T.
To carry out plastic working. By this plastic working, a tapered surface is formed on the inner surface of the hole 11 as shown in FIG. At this time, the axial length of the tapered surface formed on the inner surface of the hole 11 can be freely changed by changing the tapered surface T formed on the punch.

As described above, a "burr 3a (see the dotted line in the figure)" or "burr" of the workpiece is deformed on the outer peripheral edge of the hole 11 with the plastic working as described above. The processing is performed in the same manner as in the embodiment described above.
Other configurations are the same as those of the first embodiment.

As described above, according to the present invention, since a single punching punch can be used for punching, plastic working, and pressing by press working, holes can be machined one by one using a conventional taper drill and reamer. For this operation, an extremely remarkable improvement in efficiency can be achieved.

In the above embodiment, a method of forming a through hole having a tapered shape by a press and a tool used for the method have been described.
The same effect can be obtained even if the holding is performed by different tools. At this time, a guide portion having the same diameter as the outer diameter of the punch portion of the hole drilling tool may be provided at the tip of the tapered surface to be plastically deformed. Further, as shown in FIG. 4, after forming a through-hole having a tapered shape in the front cylindrical body by a punch having no holding portion as shown in FIG.
May be removed by machining. Further, depending on the clearance between the outer diameter of the front tubular body of the pipe joint and the inner diameter of the sleeve 29, it is not necessary to perform the pressing process. The tool may be a separate tool for drilling and plastic working. In addition, the present invention is not limited to the through-hole having a tapered shape of a pipe joint, and the present invention can be applied to processing of a through-hole having various tapered shapes, and further, the present invention can be applied to other shapes without departing from the spirit or main features of the invention. It can be implemented in various forms. In addition, the above-described embodiment is merely an example in all aspects, and should not be construed as limiting.

[0023]

As described in detail above, according to the present invention,
Since a through hole having a tapered shape can be formed by pressing, the efficiency of drilling work can be greatly improved. In addition, by adopting the method of processing the through hole having the tapered shape, the punch is arranged in accordance with the position of the through hole having the plurality of tapered shapes, so that the plurality of tapered shapes can be formed by one pressing process. Can be formed at the same time, and it is not necessary to determine the position of the hole as in the past, and if the processing tool of the present invention is used, the drilling operation with a taper drill and the reamer finishing can be eliminated. . In addition, compared with the conventional drilling operation using a taper drill, it is not necessary to perform dimensional control associated with replacement of the drill and the reamer, and a highly accurate tapered through hole can be formed. Further, in the present invention, the generation of "burrs" and "burrs" generated at the time of drilling can be minimized, and the pipe joint can be smoothly assembled. .

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method of processing a through hole having a tapered shape according to a first embodiment of the present invention.

FIG. 2 is an enlarged view of a main part of a punching punch used for processing a through hole having the present tapered shape.

FIG. 3 is an enlarged explanatory view of a through hole having a tapered shape.

FIG. 4 is an enlarged explanatory view of another hole punch.

FIG. 5 is an enlarged view of a main part of a punch and a die used in a tapering method according to a second embodiment.

FIG. 6 is a perspective view of a die in FIG. 5;

FIG. 7 is a partial sectional view of a hole punch according to a third embodiment.

FIG. 8 is an explanatory view of an enlarged process by the hole punch shown in FIG. 7;

FIG. 9 is a sectional view of a conventional pipe joint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hole punch 1a Punch part 1b Taper processing part which has a taper surface 1c Pressing part 2,40 Die 2a Hole 3 Workpiece (front cylinder) 3a Burr 4 Fixing member 11 hole

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-59-174233 (JP, A) JP-A-5-169149 (JP, A) JP-A-56-126037 (JP, A) JP-A-4- 257305 (JP, A) (58) Field surveyed (Int. Cl. ⁶ , DB name) B21D 28/24 B21D 28/16 B21D 28/34

Claims (6)

(57) [Claims] 1. A cylindrical sleeve having a plurality of punching holes formed on the periphery thereof and a deburring blade edge at a corner of the hole on the workpiece side, and having a cylindrical shape formed on the outer periphery of a cylindrical sleeve serving as a die. The workpiece is fitted and fixed, and the workpiece is simultaneously punched with a first punch having a diameter smaller than that of the die formed in each of the plurality of punches arranged corresponding to the plurality of punching holes. After that, the second punch is inserted into the guide with the hole, and at least a part of the hole is plastically worked into a tapered shape by the second punch. In addition to preventing the formation of burrs formed at the outer peripheral edge of the hole by plastic working, the work-side burr generated at the time of punching is cut by the cutting edge formed in a die, and the work is tapered to the work. Shape Hole processing method of forming a through hole One. 2. A tool used for forming a through-hole having a tapered shape in a part of a workpiece by pressing, comprising:
The tool has a small-diameter first hole for punching a hole in the workpiece.
A punch, the second punch forming a through hole having a tapered shape at the lower end of the hole by plastically processing the hole using the punched hole as a guide, and a punch formed at an outer peripheral edge of the punched hole by plastic processing of the second punch. A presser for preventing the generation of burrs is provided, and the second punch has a round bar-shaped lower end having a predetermined length and a tapered portion continuous with the outer periphery of the first punch. A presser for slidably preventing the generation of burrs formed on the outer peripheral edge of the hole by plastic working of the second punch is provided above the punch, for working a through hole having a tapered shape. tool. 3. A tool and a die used when a tapered through hole is formed in a workpiece by pressing, said tool comprising: a first punch having a small diameter for punching a hole in said workpiece; A second punch for forming the through hole having a tapered shape by plastically processing the hole using the hole as a guide is formed continuously in the axial direction, and the die is formed separately for each tool. In addition, a tapered surface is formed on the inner peripheral surface, and the tapered member fitted to the inner peripheral surface has a tapered shape characterized by being pushed toward the inner peripheral surface of the workpiece. Tools and dies for drilling through holes. 4. The tool according to claim 1, wherein a pressing portion is formed at an upper portion of the second punch for preventing occurrence of burrs formed on an outer peripheral edge of the hole by plastic working of the second punch. A tool and a die for machining a through hole having a tapered shape according to claim 3. 5. A tapered portion is formed at a lower end of the second punch so as to form a tapered surface near an inner peripheral surface of the workpiece in the second punch. A tool and a die for machining a through hole having a tapered shape according to claim 3 or 4. 6. The tool is characterized in that a pressing portion formed on the outer peripheral edge of the hole by plastic working of the second punch to prevent burrs is slidably provided on the tool. The tapered through-hole machining tool and die according to any one of claims 3 to 5.